SOLUTION: Solve -4y-20=5x -3x+15=-2y (By elimination method)

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Question 1157580: Solve
-4y-20=5x
-3x+15=-2y
(By elimination method)
Answer by MathLover1(20849) About Me  (Show Source):
You can put this solution on YOUR website!
Solve (By elimination method)
-4y-20=5x.........eq.1
-3x%2B15=-2y........eq.2
-----------------------------------write in standard form
-5x-4y=20.........eq.1.......both sides multiply by 3
-3x%2B2y=-15........eq.2.......both sides multiply by 5
------------------------------------
-15x-12y=60.........eq.1
-15x%2B10y=-75........eq.2
-----------------------------------subtract eq.2 from eq.1

-15x-12y-%28-15x%2B10y%29=60-%28-75%29

-15x-12y%2B15x-10y=60%2B75.......eliminate x

-22y=135

y=135%2F-22

highlight%28y=-135%2F22%29-> exact solution

go to

-4y-20=5x.........eq.1, substitute y

-4%28-135%2F22%29-20=5x.........solve for x

270%2F11-20=5x

50%2F11=5x

x=%2850%2F11%29%2F5

highlight%28x=10%2F11%29